Data centres are environments in which computing equipment is located. Typically, a data centre houses a plurality of computers arranged in fixtures, such as cabinets or racks. Each computer may include a combination of components, such as one or more processors and associated memory devices, storage devices such as magnetic or optical based storage devices, and one or more communication devices.
Due to the concentration of computing equipment in a data centre, cooling is required in order to maintain a temperature within the data centre to an acceptable level. Typically, one or more computer-room air conditioning (CRAC) units are arranged to receive warm air from, and supply cooled air to, the data centre. Each CRAC unit comprises one or more fans to draw data centre air into the CRAC unit. The in-drawn air is cooled as it passes through the CRAC unit, for example by exposure to a heat exchanger comprising chilled water, and expelled into a cold area of the data centre to cool the computing equipment. Each item of computing equipment generally comprises a fan to draw air therethrough to cool electronic components and/or devices within the computing equipment. Air is expelled from the computing equipment into a hot area of the data centre for return to the one or more CRAC units.
FIG. 1 illustrates air pressure against airflow within a data centre having 1, 2 or 3 operational CRAC units and between one and twenty four items of computing equipment each having an internal fan. Airflow and pressure for a single CRAC unit is represented by line 101; line 102 represents airflow and pressure for two CRAC units operating in parallel; and line 103 represents three CRAC units operating in parallel. Airflow and pressure for one item of the computing equipment is represented by line 104, whilst pressure and airflow for twenty four items of computing equipment arranged in parallel is shown by line 105. Airflow through intermediate numbers of items of computing equipment is shown in FIG. 1, although each line is not individually labelled for clarity. It will be noted that twenty four items of computing equipment are described for example only and the data centre may comprise further items of computing equipment.
An operational variance 106 in controlling airflow through each CRAC units exists. The variance in controlling the airflow through three CRAC units is shown in FIG. 1(a) and the effect 107 of the CRAC unit operating variance on the twenty four items of computing equipment is shown in FIG. 1(b) which represents a close-up of the same part in FIG. 1(a). Due to the relatively high operational air pressure of the CRAC units compared to the lower operating pressure of each item of computing equipment, a relatively small variation in CRAC unit air pressure has a relatively large effect on the cooling system and cooling of the computing equipment. This is troublesome for the computing equipment, particularly since many complex items of computing equipments, such as servers and the like, include a plurality of temperature sensors and complex cooling control systems which are greatly affected by the variation in CRAC unit airflow output.
It is an object of embodiments of the invention to at least mitigate one or more of the problems of the prior art.